The solution structure of the dicerium(III) complex of the N-terminal domain of calmodulin (Ce2-TR1C hereafter) has been solved employing paramagnetic T1 relaxation enhancements and pseudocontact shifts introduced by the Ce3+ ions, together with conventional NOE constraints. The use of pseudocontact shift constraints constitutes the first attempt to locate metal ions within a protein structure by NMR. Like calcium(II), paramagnetic cerium(III) has been found to bind to the two metal binding sites of the TR1C fragment of calmodulin in a cooperative manner. Due to the presence of pseudocontact interactions between the Ce3+ ions and protons of the 76-residue protein, the 1H NMR spectra of the complex show resonances shifted between +22 and -9 ppm. Eighty percent of its proton resonances could be assigned through a standard approach using TOCSY/COSY and NOESY spectra and through 1D NOE difference spectra for the broad resonances of protons close to the paramagnetic ions. A family of structures was calculated by means of the torsion angle dynamics program DYANA [Güntert, P., Mumenthaler, C., & Wüthrich, K. (1996) XVIIthInternational Conference on Magnetic Resonance inBiological Systems (Abstract)] using 1012 NOEs. Longitudinal proton relaxation times helped to roughly define the position of the metal ions within the protein. A total of 381 pseudocontact shift constraints, whose evaluation and use are critically discussed, have then been added to further refine the metal coordinates within the protein frame and to improve the structure resolution. A dramatic resolution improvement of the metal coordinates together with a sizable resolution improvement in the regions close to the paramagnetic centers, where the number of NOEs is low, is observed. The good quality of the solution structure permitted a meaningful comparison with the solid-state structure of calcium-loaded calmodulin at 1.7 A resolution [Chattopadhyaya, R., Meador, W. E., Means, A. R., & Quiocho, F. A. (1992) J. Mol. Biol. 228, 1177]. The Ce2-TR1C complex is overall more compact than the Ca form.
Solution NMR Structure of apo-calmodulin in complex with the IQ motif of Human Cardiac Sodium Channel Na(V)1.5.
Solution NMR Structure of apo-calmodulin in complex with the IQ motif of Human Cardiac Sodium Channel Na(V)1.5.
Solution NMR Structure of apo-calmodulin in complex with the IQ motif of Human Cardiac Sodium Channel Na(V)1.5.
J Mol Biol. 2010 Dec 14;
Authors: Chagot B, Chazin WJ
The function of the human voltage-gated sodium channel Na(V)1.5 is regulated in part by intracellular calcium signals. The ubiquitous calcium sensor protein calmodulin (CaM) is an important part of the complex calcium-sensing apparatus in Na(V)1.5. CaM interacts with an IQ...
nmrlearner
Journal club
0
12-21-2010 01:00 PM
[NMR paper] NMR solution structure of a complex of calmodulin with a binding peptide of the Ca2+
NMR solution structure of a complex of calmodulin with a binding peptide of the Ca2+ pump.
Related Articles NMR solution structure of a complex of calmodulin with a binding peptide of the Ca2+ pump.
Biochemistry. 1999 Sep 21;38(38):12320-32
Authors: Elshorst B, Hennig M, Försterling H, Diener A, Maurer M, Schulte P, Schwalbe H, Griesinger C, Krebs J, Schmid H, Vorherr T, Carafoli E
The three-dimensional structure of the complex between calmodulin (CaM) and a peptide corresponding to the N-terminal portion of the CaM-binding domain of the...
nmrlearner
Journal club
0
11-18-2010 08:31 PM
NMR solution structure of the N-terminal domain of hERG and its interaction with the
NMR solution structure of the N-terminal domain of hERG and its interaction with the S4-S5 linker.
NMR solution structure of the N-terminal domain of hERG and its interaction with the S4-S5 linker.
Biochem Biophys Res Commun. 2010 Nov 2;
Authors: Li Q, Gayen S, Chen AS, Huang Q, Raida M, Kang C
The human Ether-à-go-go Related Gene (hERG) potassium channel mediates the rapid delayed rectifier current (IKr) in the cardiac action potential. Mutations in the 135 amino acid residue N-terminal domain (NTD) cause channel dysfunction or...
[NMR paper] Solution structure of the 30 kDa N-terminal domain of enzyme I of the Escherichia col
Solution structure of the 30 kDa N-terminal domain of enzyme I of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system by multidimensional NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-acspubs.jpg Related Articles Solution structure of the 30 kDa N-terminal domain of enzyme I of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system by multidimensional NMR.
Biochemistry. 1997 Mar 4;36(9):2517-30
Authors: Garrett DS, Seok YJ, Liao DI, Peterkofsky A, Gronenborn AM, Clore GM
...
Solution structure of the paramagnetic complex of the N-terminal domain of calmodulin
Linear Mode
